# Java > Use OpenTelemetry to instrument your Java application and send telemetry data to Last9 Source: https://last9.io/docs/integrations/languages/java/ Use OpenTelemetry to instrument your Java application and send telemetry data to Last9. You can run OpenTelemetry Collector or send the telemetry directly from the application. Read the [setup guide](https://last9.io/blog/opentelemetry-java-guide-with-examples/) for more details. ## Instrumentation packages Download the OpenTelemetry Java agent JAR file and place it in the project root directory. ```bash curl -L https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases/latest/download/opentelemetry-javaagent.jar -o opentelemetry-javaagent.jar ``` The latest `opentelemetry-javaagent.jar` can be found in the releases section of the [opentelemetry-java-instrumentation](https://github.com/open-telemetry/opentelemetry-java-instrumentation) repository. The agent supports Java 8 and above. To pin a specific version instead of tracking the latest release, use the versioned download URL. ```bash curl -L https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases/download/v2.30.0/opentelemetry-javaagent.jar -o opentelemetry-javaagent.jar ``` ## Environment variables Set the following environment variables. ``` OTEL_EXPORTER_OTLP_ENDPOINT={{ .Logs.WriteURL }} OTEL_SERVICE_NAME= OTEL_EXPORTER_OTLP_HEADERS=Authorization={{ .Logs.AuthValue }} OTEL_TRACES_EXPORTER=otlp OTEL_METRICS_EXPORTER=otlp OTEL_LOGS_EXPORTER=otlp OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf OTEL_TRACES_SAMPLER="always_on" OTEL_RESOURCE_ATTRIBUTES="deployment.environment=local" OTEL_INSTRUMENTATION_LOGBACK_APPENDER_EXPERIMENTAL_CAPTURE_MDC_ATTRIBUTES="*" OTEL_LOG_LEVEL=error ``` Depending on your Cloud environment, enable following: ``` OTEL_RESOURCE_PROVIDERS_AWS_ENABLED=true OTEL_RESOURCE_PROVIDERS_GCP_ENABLED=true OTEL_RESOURCE_PROVIDERS_AZURE_ENABLED=true ``` ## System Properties Alternatively, you can also set system properties for the configuration. ``` # otel.properties file otel.exporter.otlp.endpoint: {{ .Logs.WriteURL }} otel.service.name: otel.exporter.otlp.headers: Authorization={{ .Logs.AuthValue }} otel.traces.exporter: otlp otel.metrics.exporter: otlp otel.logs.exporter: otlp otel.exporter.otlp.protocol: http/protobuf otel.traces.sampler: always_on otel.resource.attributes: "deployment.environment=staging" otel.instrumentation.logback-appender.experimental.capture-mdc-attributes: "*" ``` Depending on your Cloud environment, enable following: ``` otel.resource.providers.aws.enabled: true otel.resource.providers.gcp.enabled: true otel.resource.providers.azure.enabled: true ``` You can either use a properties file or use the runtime syntax for setting system properties as follows. ``` java -javaagent:path/to/opentelemetry-javaagent.jar -Dotel.exporter.otlp.endpoint={{ .Logs.WriteURL }} -Dotel.service.name= -Dotel.exporter.otlp.headers=Authorization={{ .Logs.AuthValue }} -Dotel.traces.exporter=otlp -Dotel.metrics.exporter=otlp -Dotel.logs.exporter=otlp -Dotel.exporter.otlp.protocol=http/protobuf -Dotel.instrumentation.logback-appender.experimental.capture-mdc-attributes="*" -Dotel.traces.sampler=always_on -Dotel.resource.attributes="deployment.environment=staging" -jar myapp.jar ``` ### Caveat Older Java OpenTelemetry may require adding `%20` between the `Basic` and the actual authorization header. If you receive 401 error from the Last9 Opentelemetry endpoint, update the `OTEL_EXPORTER_OTLP_HEADERS` as follows. ``` Authorization=Basic%20 ``` ## Start the application 1. You can start your application specifying the `-javaagent` parameter now: ```shell java -javaagent:path/to/opentelemetry-javaagent.jar -jar myapp.jar ``` 2. You can specify an environment variable that automatically adds the `-javaagent` parameter to your JVM: ```shell export JAVA_TOOL_OPTIONS="-javaagent:path/to/opentelemetry-javaagent.jar" java -jar myapp.jar # or current build command ``` The application will send telemetry data such as logs, traces, and metrics to Last9. ## Capture HTTP request/response bodies :::caution Capturing HTTP bodies increases trace data volume and may expose sensitive data (PII/PHI). Use the configuration options below to control what gets captured, and always pair with PII redaction at the collector level. ::: Add HTTP request and response body capture to your traces with the `java-otel-body-capture` extension. Bodies appear as `http.request.body` and `http.response.body` span attributes — no changes to your application code required. Works with Spring Boot 2.x (`javax.servlet`) and Spring Boot 3.x (`jakarta.servlet`), as well as any app running on Tomcat, Jetty, or Dropwizard. 1. **Download the extension JAR** Download `last9-otel-body-capture.jar` from the [latest release](https://github.com/last9/java-otel-body-capture/releases). 2. **Add it to your startup command** ```bash java -javaagent:opentelemetry-javaagent.jar \ -Dotel.javaagent.extensions=last9-otel-body-capture.jar \ -jar your-app.jar ``` Every HTTP span now carries `http.request.body` and `http.response.body` as attributes. ### Configuration All options are system properties. The defaults are production-safe out of the box. | Property | Default | Description | | ---------------------------------------- | --------------------------------------------- | --------------------------------------------- | | `otel.bodycapture.enabled` | `true` | Master switch | | `otel.bodycapture.capture_request_body` | `true` | Capture request bodies | | `otel.bodycapture.capture_response_body` | `true` | Capture response bodies | | `otel.bodycapture.max_body_size_bytes` | `8192` | Truncates larger bodies with `...[TRUNCATED]` | | `otel.bodycapture.capture_on_error_only` | `false` | Only attach bodies on 4xx/5xx | | `otel.bodycapture.exclude_paths` | `/health,/ready,/metrics` | Skip these path prefixes | | `otel.bodycapture.include_paths` | _(all)_ | Restrict to these path prefixes only | | `otel.bodycapture.content_types` | `application/json,application/xml,text/plain` | Only capture these content types | :::tip[Production recommendation] Set `capture_on_error_only=true` in production. You get full request and response bodies on every failure, zero overhead on happy paths. ::: ```bash java -javaagent:opentelemetry-javaagent.jar \ -Dotel.javaagent.extensions=last9-otel-body-capture.jar \ -Dotel.bodycapture.capture_on_error_only=true \ -Dotel.bodycapture.include_paths=/api/ \ -jar your-app.jar ``` ### PII/PHI redaction at the collector Redact sensitive data at the OTel Collector so the pattern is centralized and no app redeployment is needed to update it: ```yaml processors: transform/redact-pii: trace_statements: - context: span statements: # SSN - replace_pattern(attributes["http.request.body"], "\\b\\d{3}-\\d{2}-\\d{4}\\b", "***-**-****") - replace_pattern(attributes["http.response.body"], "\\b\\d{3}-\\d{2}-\\d{4}\\b", "***-**-****") # Email - replace_pattern(attributes["http.request.body"], "[a-zA-Z0-9._%+\\-]+@[a-zA-Z0-9.\\-]+\\.[a-zA-Z]{2,}", "****@****.***") - replace_pattern(attributes["http.response.body"], "[a-zA-Z0-9._%+\\-]+@[a-zA-Z0-9.\\-]+\\.[a-zA-Z]{2,}", "****@****.***") service: pipelines: traces: processors: [transform/redact-pii, batch] ``` For a complete working example, see the [HTTP body capture example](https://github.com/last9/opentelemetry-examples/tree/main/java/http-body-capture). --- ## Troubleshooting Please get in touch with us on [Discord](https://discord.com/invite/Q3p2EEucx9) or [Email](mailto:support@last9.io) if you have any questions.